As an analysis device which analyzes a component amount contained in a sample, an automatic analysis device is known which measures the intensity of transmitted light or scattered light having a single or multiple wavelengths obtained by emitting light from a light source to a reaction solution in which the sample and a reagent are mixed with each other, and which calculates the component amount, based on a relationship between light intensity and density.
According to an automatic analysis device disclosed in PTL 1, optically transparent reaction cells are circumferentially arrayed on a reaction disk which repeatedly rotates and stops. While the reaction disk rotates, a time-dependent change (reaction process data) of the light intensity which is caused by a reaction is measured at regular time intervals, for approximately 10 minutes, by a transmitted light measurement unit arranged in advance. After the reaction is completed, a reaction vessel is cleaned by a cleaning mechanism, and is reused for another analysis.
In a case of the reaction of the reaction solution, two analysis fields such as colorimetric analysis using a color reaction of a substrate and an enzyme and homogeneous immunological analysis using an agglutination reaction caused by binding of an antigen and an antibody are present in a broad sense. In the latter homogeneous immunological analysis, a measurement method is known such as immune-nephelometry and a latex agglutination method.
According to the immune-nephelometry, a reagent containing the antibody is used, an immune complex with a measurement object (antigen) contained in a sample is generated, and both of these are optically detected so as to quantify a component amount thereof. According to the latex agglutination method, a reagent containing latex particles in which the antibody is sensitized on (bound with) the surface is used, latex particles are coagulated through an antigen-antibody reaction with the antigen contained in a sample, and both of these are optically detected so as to quantify a component amount thereof.
In addition, an automatic analysis device disclosed in PTL 2 is also present which measures the coagulation ability of the blood. The blood flows in the blood vessel while holding liquidity. However, if the blood flows out once from a body, coagulation factors present in plasma and platelets are serially activated, and fibrinogen in the plasma is converted into fibrin and precipitated, thereby leading to hemostasis.
This coagulation ability of the blood includes exogenous ability by which the blood leaking out from the blood vessel coagulates and endogenous ability by which the blood in the blood vessel coagulates. Measurement items relating to the coagulation ability of the blood (blood clotting-time) include prothrombin time (PT) of an extrinsic blood coagulation reaction test, activated partial thromboplastin time (APTT) of an intrinsic blood coagulation reaction test, and a fibrinogen amount (Fbg).
Any of these items is configured so that fibrin precipitated by adding a reagent for initiating a coagulation reaction is detected by using optical, physical, and electrical methods. As a method of using optical means, a method is known in which a clotting-time is calculated by emitting light to a reaction solution and detecting a time-dependent intensity change in scattered light or transmitted light from the fibrin precipitated in the reaction solution. According to a representative automatic analysis device of blood coagulation in PTL 2, a blood clotting-time item requires photometric data at intervals of 0.1 seconds. Thus, the reaction is performed in a separate photometric port. If the reaction solution coagulates, a reaction vessel cannot be reused by cleaning. Thus, the reaction vessel has to be discarded. In addition to blood clotting-time measurement, a blood coagulation/fibrinolysis test field also includes coagulation factor measurement and coagulation/fibrinolysis marker measurement. Although the coagulation factor is mainly analyzed by the blood clotting-time measurement, a coagulation/fibrinolysis marker is analyzed by a synthetic substrate method using a chromogenic synthetic substrate or by the previously described latex agglutination method. The blood clotting-time item substantially and stereotypically includes PT, APTT, and Fbg in the related art. In contrast, in addition to D-dimer or fibrin/fibrinogen degradation products (FDP), a coagulation/fibrinolysis marker item includes a soluble fibrin monomer complex (SFMC) and a plasmin-α2 plasmin inhibitor (PIC). The coagulation/fibrinolysis marker item is expected to increase in the future, since there is a demand for early diagnosis/treatment of disseminated intravascular coagulation (DIC). Accordingly, it is desirable to improve a throughput of the automatic analysis device. The blood clotting-time measurement is usually completed within approximately 3 minutes. Therefore, it is possible to maintain the improved throughput by discarding/supplying a reaction vessel after the measurement is completed. On the other hand, according to the synthetic substrate method or the latex agglutination method, the reaction usually continues for 10 minutes. In most cases, the measurement time is longer than that for an item of the clotting-time method. However, according to the automatic analysis device of the blood coagulation in PTL 2, not only the clotting-time but also the coagulation/fibrinolysis marker is analyzed by using a fixed photometric port. Consequently, if there is a measurement request for a synthetic substrate item or a latex agglutination item, there is a problem in that the throughput of the device is extremely decreased. It is conceivable to employ a method of increasing the number of measurement ports in order to suppress the decrease in the throughput of the blood coagulation analysis device. However, the device cost inevitably increases, since the number of light sources, light receiving elements, and amplifier circuits which are required for detection also increases.